Having trouble blowing out lines

[CSteen]

This is my second year closing my pool and for some reason I can't seem to get all of the water out of my lines.

I've drained the water level to just below the returns and drained out as much as I can on the equipment side of things. I'm using a 5hp shop vac with a high tech custom water bottle duct taped to it to blow into the opening of a Gizzmo installed in my skimmer. When I start blowing I see a dribble come out of the returns, but no apparent air coming out of them. I have my multi port valve set to recirculate and everything is closed up tight.

I noticed water in the pipe from the skimmer so I primed the pump and ran it for a couple of minutes to drain out as much as I could.

I have a feeling I got my order off operations mixed up somewhere. Any theories as to why air doesn't seem to be taking the full trip to the returns?

 

[CSteen]

Also worth noting that my pool has two returns, no main drain, and a vac line that has been shut off at the equipment pad because of a cracked pipe in the line.

 

[awtrizzle]

Do you have two skimmers? Sometimes if I don’t plug up the suction really good on the other return, it won’t create enough pressure to blow the excess water/air out of my returns.

 

[CSteen]

Do you have two skimmers? Sometimes if I don’t plug up the suction really good on the other return, it won’t create enough pressure to blow the excess water/air out of my returns.

Nope, only one skimmer. I tried plugging one return as well with no luck.

 

[awtrizzle]

Only thing I can think of is to mentally follow the path of the air that you’re trying to blow through the system. Make sure the valves are open and shut properly.
I’m sure you’ve done this already but it’s the only thing I can think of. Some pictures of your pad may help as well. Maybe not me, but I could help someone else.

 

[Catanzaro]

CSteen:

If I am understanding correctly, you have made up some sort of water bottle gadget and you are trying to blow air from the Gizzmo at the skimmer with a shop vac back to the return lines. Do you have a MPV valve, and what do you have it set on? Is your skimmer port threaded? I believe you are working way to hard here.

Considering you have no main drain, why not use an NPT fitting at the pump with an air compressor. You can isolate the suction (skimmer side) and return side and clear the lines properly. If your MPV is set properly, then the distance from the skimmer back to the filter, and to the returns is long enough where there may not be enough volume from the shop vac.

This year I used a very small shop vac to clear lines in a spill over spa in where there was no water. The run was maybe about 50' at most and there was a total of 6 jets. Although, the lines had already been cleared with a pool blower the first time. Hard to tell.

Also, were you successful the previous year? If so, think back on what you did and why?

 

[PoolguyinCT]

This is were antifreeze can come in handy.. just shoot into the topside & when you see it exit on poolside, you will know you have purged the hills and valleys in the piping & good to go.

Since this method is only a visual indicator, I bet you can do it with a half gallon.

 

[PoolGate]

Is blowing air in the lines like draining water in that you need a vent (of sorts) to enable the flow?

 

[PoolguyinCT]

Gate - sorta the opposite sometimes you have to run/jockey the plugs.

 

[Catanzaro]

Is blowing air in the lines like draining water in that you need a vent (of sorts) to enable the flow?

Blowing air in any line is exactly what you stated, and that is blowing air with either a pool blower, air compressor or shop vac through the line from a starting point. Take a 5' hose and fill it with water and blow air through it with your mouth and water will come out. Small example as pools are on such a larger scale. Flow of air or volume is created by machines that create air.

you need a vent (of sorts) to enable the flow?

It is not really a vent, but an opening to allow water out.

 

[anthonypool89]

I would not even consider draining the pool water level down below the return lines. That, for me, would be aLOT of water. If sufficient air bubbles are coming out of the return lines into the pool water, then most of the water is out of the pipes. The air pressure will push the water out first (or most of it) before any air comes through. Once the air bubbles are constant, it's ok to plug the return lines while the air is still on, and then you're done with those. I've never heard of a set-up where you'd start adding air from the skimmer (?)

 

[anthonypool89]

Is blowing air in the lines like draining water in that you need a vent (of sorts) to enable the flow?

...the water being blown through the lines, at least in my case, simply goes back into the pool. It doesn't really take all that much pressure either. With my old a/c I used to only use about 5-6 lbs. of pressure. I don't like that my new compressor's gauge isn't calibrated below 10, so it's sort of a guess as to how much air pressure is being used. Unless the line being blown is somehow blocked on the opposite end of where the air is being applied, it'll empty out, followed by air bubbles.

 

[CSteen]

CSteen:

If I am understanding correctly, you have made up some sort of water bottle gadget and you are trying to blow air from the Gizzmo at the skimmer with a shop vac back to the return lines. Do you have a MPV valve, and what do you have it set on? Is your skimmer port threaded? I believe you are working way to hard here.

Considering you have no main drain, why not use an NPT fitting at the pump with an air compressor. You can isolate the suction (skimmer side) and return side and clear the lines properly. If your MPV is set properly, then the distance from the skimmer back to the filter, and to the returns is long enough where there may not be enough volume from the shop vac.

This year I used a very small shop vac to clear lines in a spill over spa in where there was no water. The run was maybe about 50' at most and there was a total of 6 jets. Although, the lines had already been cleared with a pool blower the first time. Hard to tell.

Also, were you successful the previous year? If so, think back on what you did and why?

Hi Catazaro. The shop vac did work for me last year. Thinking back I may have blown out the lines before draining. Not sure how that would have made things easier, though.

Blowing air through one side at a time makes sense, but I don't own a compressor. I'm also unclear on which npt fitting I would need and where I would hook that up. Any chance you could recommend a compressor that would do the job that I could also run an airbrush off of?

 

[Catanzaro]

Please read through the posts. The NPT fitting goes to the pump housing (picture in post # 1 of concept thread). If you take the drain plug out and bring to Home Depot or Lowes, they will match it up. Regarding a compressor, below is some additional information.


Concept of closing an IG Swimming Pool (real in depth information):

The concept of closing an in ground swimming pool

Blow through plug that can be used with an air compressor:

Winter Pool Plug with Valve for 1-1/2 Inch Fitting, with Blow Thru Valve - No. 10 AQWPV-10

A compressor that someone purchased:

Closing: blosing out lines, water level and then some

I am actually going to purchase a small air compressor for my own needs. My large one is tucked away in a corner and the small car in the garage has to be moved each time I need it (large compressor). At least the small one will do the trick for other needs.

 

[CSteen]

Please read through the posts. The NPT fitting goes to the pump housing (picture in post # 1 of concept thread). If you take the drain plug out and bring to Home Depot or Lowes, they will match it up. Regarding a compressor, below is some additional information.


Concept of closing an IG Swimming Pool (real in depth information):

The concept of closing an in ground swimming pool

Blow through plug that can be used with an air compressor:

Winter Pool Plug with Valve for 1-1/2 Inch Fitting, with Blow Thru Valve - No. 10 AQWPV-10

A compressor that someone purchased:

Closing: blosing out lines, water level and then some

I am actually going to purchase a small air compressor for my own needs. My large one is tucked away in a corner and the small car in the garage has to be moved each time I need it (large compressor). At least the small one will do the trick for other needs.

I appreciate the links. That should set me on the right path. Thanks for the reply.

 

[CSteen]

So, if I understand correctly, I need to get a plug similar to what I use on my returns to cap each line from my pump basket. For suction side(skimmer) I'll cap the pipe that is sending water out of my pump and use the compressor with NPT fitting to blow about 30psi of air into the opening for the pump drain plug until water stops spraying out of the skimmer. Then I'll switch to capping the input pipe for the pump and blow air(mpv on recirculate) until water stops flowing from returns. Sound right?

Looking at this compressor: 8 gal. 2 HP 125 PSI Oil Lube Air Compressor

Will that do the trick?

 

[Catanzaro]

You are not capping the suction and return port in the pump basket. You could use the blow out plugs and leave them there, but that would be the only reason. The compressor you are looking at is fine. Just do not over pressure the system. 15-30 psi at most.

 

[CSteen]

You are not capping the suction and return port in the pump basket. You could use the blow out plugs and leave them there, but that would be the only reason. The compressor you are looking at is fine. Just do not over pressure the system. 15-30 psi at most.

Ok, sorry, still not 100% sure I understand. Didn't quite grasp how the blowout plug works at first. Would I be hooking the compressor to the blowout plug at the suction and return ports in the basket to blow out the lines?

 

[Catanzaro]

Ok, sorry, still not 100% sure I understand. Didn't quite grasp how the blowout plug works at first. Would I be hooking the compressor to the blowout plug at the suction and return ports in the basket to blow out the lines?

If you want to, then YES you can work this way. The plugs have a positive seal and do not allow air to travel back. You can use these in the skimmer housing/port as well and push air to remove water towards the pump basket (leave suction side open). These work well for the main drain, but make sure if you have a shut off valve at equipment pad to close off so all air travels to the main drain.

If not, just use an NPT fitting at the pump housing with an air compressor. You are basically taking air to move water and close the end of each run with with a plug or an air lock for the main drain.

 

[CSteen]

If you want to, then YES you can work this way. The plugs have a positive seal and do not allow air to travel back. You can use these in the skimmer housing/port as well and push air to remove water towards the pump basket (leave suction side open). These work well for the main drain, but make sure if you have a shut off valve at equipment pad to close off so all air travels to the main drain.

If not, just use an NPT fitting at the pump housing with an air compressor. You are basically taking air to move water and close the end of each run with with a plug or an air lock for the main drain.

I tried again with my compressor and I'm still not having success. How long should it need to run before I start seeing water move?

The blowthru plug I ordered was bigger than most of my plumbing, so I just ended up attaching my compressor hose to where the pump drain plug was. I tried closing off the return side with a plug in the pump basket, and alternately used the blowthru plug(capped) to try to move things the other way. I saw a tiny bit of movement at the returns, and I could see the water level in the Gizmo rise a little when I tried that side. But nothing dramatic. Where am I going wrong?

Temps are starting to dip into the 20s and I'm getting worried about my pipes.